Self-lubricating bushings vs. relubricable bushings: how to choose

In short, self-lubricating bushings are ideal when maintenance needs to be kept to a minimum or when the lubrication point is difficult to access. Relubricable bushings, on the other hand, are suitable when periodic lubrication can be scheduled and the application operates under demanding conditions, with exposure to shock loads and contaminants.

The operating conditions a bushing is subjected to have a significant impact on its performance and service life.
Loads, sliding speed, vibrations and shock loads, temperature, exposure to contaminants or chemical agents, and the possibility of relubrication: every application has specific operating conditions that can affect a bushing's performance and long-term durability.

That's why there is no one-size-fits-all solution. Choosing the right bushing for the specific application makes all the difference in terms of reliability, efficiency and maintenance costs.

Self-Lubricating or relubricable bushings?

Choosing between a self-lubricating bushing and a relubricable bushing depends on the operating conditions and the specific requirements of the application.

Self-lubricating solutions are particularly suitable when the aim is to reduce maintenance or when access to the component is difficult. Relubricable bushings, on the other hand, allow lubricant to be replenished and may be the preferred choice for applications requiring scheduled lubrication.

In this article, we'll explore the different types of DJA MOND self-lubricating and relubricable bushings from JFK Group, highlighting their features, advantages and main applications to help you identify the most suitable solution for your needs.

Self-lubricating bushings: types and applications

Dry-running self-lubricating bushings with solid lubricant inserts

These sliding components require no lubrication and are suitable for heavy loads and low sliding speeds.
They consist of a solid body with solid lubricant inserts based on graphite and/or PTFE. The body can be made of copper alloy (BG.. series), steel (AG.. series) or cast iron (CG.. series).
During operation, the solid lubricant forms a thin film that covers both surfaces, preventing direct metal-to-metal contact.
Dry-running self-lubricating bushings with solid lubricant inserts are used in a wide range of applications. Depending on the material, they can be found in sectors ranging, for example, from the food industry to crane support systems.

Multilayer self-lubricating bushings with PTFE composite

Also known as dry bearings, DJA MOND PT..SL bushings consist of a low-carbon steel backing, a porous bronze layer and a self-lubricating PTFE layer.
Thanks to this PTFE layer, they are maintenance-free, suitable for high sliding speeds and offer good frictional properties, with low wear and high load-bearing capacity.
Multilayer self-lubricating bushings with PTFE composite are used across a wide range of industries, from household appliances to the automotive industry, and from the pharmaceutical sector to the food industry.

Sintered bronze and iron bushings

Sintered self-lubricating bearings are manufactured using the most modern and advanced powder metallurgy processes.
Featuring a controlled porous structure, BZ../FE.. sintered bushings are oil-impregnated, gradually releasing lubricant during normal operation to form a self-lubricating film.
They are generally suitable for applications involving high rotational speeds and low loads.

Engineering plastic bushings

EPB.. series engineering plastic bushings offer a versatile and efficient solution for industrial applications requiring low weight, reduced maintenance and good wear resistance.
Made from EPB.. engineering plastic, they are widely used in applications involving light to medium loads and operating temperatures below 80°C.
Compared with traditional metal solutions, engineering plastic bushings offer high resistance to corrosion, moisture and many chemical agents, making them particularly suitable for harsh environments and applications where improved operational cleanliness is required.

Fiber bushings

The outer material of the FWB.. series fiber bushings consists of high-strength glass fibers reinforced with epoxy resin, while the lubricating layer is made of PTFE-wrapped fibers or special lubricating fibers.
This structure has been specifically designed to provide exceptional wear resistance and a low coefficient of friction under high-load, low-speed operating conditions.

Relubricable bushings: types and applications

Multilayer relubricable bushings with POM

POM plain bearings can be considered pre-lubricated because they require only a minimal amount of lubricant to operate optimally over an extended period.
They consist of a low-carbon steel backing that provides mechanical strength. The porous sintered bronze layer is impregnated and coated with POM (or PEEK), with pockets formed on its surface to retain grease and collect any impurities that may get between the shaft and the bushing.
The PT..RK series multilayer relubricable bushings with POM are suitable for applications requiring minimal maintenance and involving severe operating conditions.
Particularly suitable for rotational and oscillating movements, they have low sensitivity to edge loading and are water-repellent. They also offer good damping properties, making them resistant to impact loads.
The pockets on their surface make them ideal for applications operating in dirty environments where continuous or frequent lubrication is not possible (e.g. agricultural machinery, construction equipment and material handling applications in general).

Case-hardened bushings

The BAC.. case-hardened bushings are designed for applications requiring high wear resistance, load-carrying capacity and a long service life, even under demanding operating conditions.
Thanks to the case-hardening treatment, the bushing surface achieves high surface hardness while retaining a tough core, capable of absorbing impacts and mechanical stresses.
The specific manufacturing process used for these bushings ensures excellent wear and anti-seizure performance, guaranteeing reliability, operational precision and continuous operation even in the most demanding industrial applications. The low surface roughness achieved after machining also helps reduce the coefficient of friction, improving efficiency and smoothness of movement.
After initial greasing, the BAC.. case-hardened bushings allow relubrication intervals of up to 550 hours, depending on operating conditions and the application environment.
The range includes various standard types designed to meet the requirements of the most common industrial applications, including material handling systems, automation, mechanical power transmission and industrial machinery.

Wrapped bronze bushings

This type of bushing is made of tin bronze, a material that ensures high resistance to wear, seizure, high temperatures and corrosion, as well as a high fatigue limit.
The DJA MOND PBC.. series wrapped bronze bushings are particularly distinguished by their thin walls. Thanks to this feature, for the same shaft diameter and operating loads, they require less installation space than a machined bushing or a bearing.
The sliding surface is machined and features either diamond-shaped indentations (PBC..AR) or through-holes (PBC..FP), which increase lubricant storage capacity, or diamond-shaped indentations filled with solid lubricant (PBC..ARG).
Wrapped bronze bushings are the ideal choice for machinery operating in the presence of contaminants, impacts and/or vibrations, such as agricultural machinery, lifting equipment, construction machinery and similar applications.

Bimetallic Bushings

The BJ.. bimetallic bushing consists of a steel backing, which provides high load-carrying capacity and excellent heat dissipation, and a sintered bronze powder layer, which ensures good wear resistance and allows the bushing to withstand high sliding speeds.
Upon request, the outer surface can be coated with a 2 μm layer of copper, providing good corrosion resistance.
Thanks to these characteristics, this type of bushing is used in the automotive industry, for example in petrol and diesel engines, pumps, industrial and agricultural machinery, lifting equipment, air conditioning systems, compressors, vehicle gearboxes, reduction gears, leaf springs, stabilizers for heavy-duty vehicles, and other applications.

DJA MOND bushings comparison table

Bushings comparison table

Application characteristics	Self-lubricating bushings					Relubricable bushings
	Multilayer bushings with PTFE composite	Dry-running bushings with solid lubricant inserts	Sintered bronze and iron bushings	Engineering plastic bushings	Fiber bushings	Multilayer bushings with POM	Case-hardened bushings	Wrapped bronze bushings	Bimetallic bushings
	Series PT..SL	Series BG../AG.. /CG..	Series BZ../FE..	Series EPB..	Series FWB..	Series PT..RK	Series BAC..	Series PB..	Series BJ..
High loads	Good	Excellent	Unsuitable	Unsuitable	Excellent	Excellent	Excellent	Suitable	Suitable
High speeds	Good	Suitable	Excellent	Unsuitable	Suitable	Good	Excellent	Suitable	Suitable
Low friction	Excellent	Good	Good	Good	Excellent	Excellent	Unsuitable	Unsuitable	Unsuitable
High temperatures	Good	Excellent	Unsuitable	Suitable	Good	Suitable	Excellent	Good	Good
Suitability for dirty environments	Unsuitable	Good	Suitable	Excellent	Good	Suitable	Unsuitable	Excellent	Excellent
Corrosion resistance	Suitable	Good	Suitable	Excellent	Excellent	Suitable	Unsuitable	Good	Suitable
Misalignment tolerance	Unsuitable	Good	Suitable	Good	Good	Suitable	Unsuitable	Suitable	Suitable
Operation with reduced clearance	Excellent	Excellent	Suitable	Unsuitable	Good	Good	Excellent	Suitable	Suitable
Response to vibration and shock loads	Suitable	Excellent	Suitable	Good	Good	Excellent	Excellent	Good	Good

Self-lubricating or relubricable bushings: which should you choose?

There is no single type of bushing that is best for every application. The choice depends on the operating conditions and the specific requirements of the application.

Self-lubricating bushings may be the right solution when maintenance interventions need to be reduced, when the component is difficult to access, or when the application requires operation without relubrication.

Relubricable bushings, on the other hand, allow the lubricant to be replenished during operation and may be particularly suitable for applications where maintenance can be scheduled or where operating conditions require periodic lubrication.

To identify the most suitable solution, it is therefore necessary to assess the type of movement, load, speed, temperature, operating environment and planned maintenance intervals.

Not sure which bushing to choose for your application?

Load, speed, temperature, type of movement and environmental conditions are just some of the parameters to consider.

Contact our technical department to identify the solution that best meets your needs.